Imprinting technology is a technology in which a mold for molding a depressions and protrusions pattern is pressed into a liquid resin or the like upon a substrate, and transfers the pattern of the mold to the resin. Depressions and protrusions patterns exist at sizes ranging from nano-scale (10 nm level) to about 100 μm, and these patterns are used in various types of fields such as semiconductor materials, optical materials, recording media, micro machines, biotechnology, environment, or the like.
Types of imprinting are exemplified by thermal imprinting, photo imprinting, or the like. Thermal imprinting presses a mold having a certain pattern formed in the surface thereof against a thermoplastic resin melted at a temperature greater than or equal to the glass transition temperature, thermally imprints the surface pattern of the mold into the thermoplastic resin, and peels off the imprinted thermoplastic resin from the mold after cooling. Photo imprinting presses the same type of mold against a photo-curable resin, causes curing of the photo-curable resin by ultraviolet radiation, and then peals the cured photo-curable resin from the mold.
In order to prevent attachment of the resin to the mold during imprinting, a release layer is arranged on the depressions and protrusions surface of the mold so as to impart releasability from the resin to the depressions and protrusions surface. However, there has been a problem in that, when the release layer adheres poorly to the mold, the release layer is shed due to imprinting. Therefore in order to solve the aforementioned problem, a method is known that treats the surface of the mold by plasma treatment or a silane coupling agent treatment so as to cause an improvement of adhesion of the mold release agent to the mold (e.g. see Patent Document 1). Moreover, a method is known that uses as the mold release agent a perfluoropolyether having functional groups that are chemically reactive with the material of the mold (e.g. see Patent Documents 2 and 3). These methods all relate to release treatment for molds of hard substances such as metal, silicon, glass, or the like.
Resin molds are being used in recent years due to general versatility and cost. Mold release agents are being used even for resin molds. However, since the resin mold and the resin to be imprinted are both resins, adhesion of the mold release agent is of a similar extent to both resins, and this results in a problem in that the release layer is transferred to the resin to be imprinted. Technology is desired for improving adhesion of the release layer to the resin mold.
In order to solve the aforementioned problems, for example, an oxide layer composed of an inorganic oxide is formed on the surface of a replica mold, and shedding of the release layer from the surface of the replica mold is prevented. Although it is possible to prevent shedding of the release layer from the oxide layer by formation of a release layer with this oxide layer interposed between the release layer and the mold, adhesion of this oxide film to the resin film is not necessarily good.
Therefore, there is a problem in that, even when the release layer and the oxide film are integrated, there still may be transfer of the integrated release layer and oxide film to the surface of the imprinted resin film.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-5841    Patent Document 2: Japanese Patent No. 4154595    Patent Document 3: Japanese Unexamined Patent Application Publication No. 2004-306030